Colorimeter



Feb. 9, 1943. R. s. EsTEY ETAL GOLORIMETER Filed April l, 1940 .HARPER mm N Patented Feb. 9, 1943 ooLoRIMETER Roger S. Estey and Kennard W. Harper, Buffalo,

N. Y., assignors to Spencer Lens Company, Buffalo, N. Y., a corporation of New York Application April 1, 1940, Serial No. 327,152

(o1. lss-14) 3 Claims.

This invention relates to colorimeters and has particular reference to a new and improved colorimeter for comparing the color of substances with certain known standards or with each other.

One of the objects of the invention is to provide a new and improved instrument of the type set forth wherein the sample under test may be quickly and easily inserted in or removed from the operative position.

Another object of the invention is to provide new and improved means whereby a portion of the instrument may be quickly and easily moved out of operative position to allow removal or insertion of the sample.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing and it will be understood that many changes in the details of construction and arrangements of parts may be made without departing from the scope of the invention as expressed in the accompanying claims. We, therefore, do not Wish to be limited to the construction shown and described as the preferred form is shown by way of illustration only.

Referring to the drawing:

Fig. 1 is a front view, partly in section, showing the construction of the new instrument;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1 looking in the direction of the arrows;

Fig. 3 is a top plan View of the instrument;

Fig. 4 is a side view, partly in section, showing the pivot means;

Fig. 5 is a sectional view taken on line 5 5 of Fig. 4 looking in the direction of the arrows.

In the production of certain oils, for example, olive oil, linseed oil, cottonseed oil, and peanut oil, as well as in the petroleum and beer industries, the matter of color has become of prime importance.

In industries such as the beer industry, it is necessary that the beer sold from time to time be exactly the same both in color and consistency as that previously sold.

In the vegetable oil industries the question of color is also particularly important to the extent that a higher or premium price is frequently paid for oils of the lighter shades.

From the above it will be seen that the question of ascertaining the color of such products is a necessary and important one. To ascertain the color of such products the usual method is to compare the color of the product with known color standards. It is, therefore, the principal object of this invention to provide a new and improved colorimeter with which it is possible to ascertain the color of such liquids and other substances more quickly and accurately than has been possible With prior art colorimeters.

Referring more particularly to the drawing wherein similar reference characters designate similar parts throughout the several views, the colorimeter shown comprises the base I, on which is positioned the sample containing portion 2, the member 3 containing the optical system and eyepiece portion 4.

The base I has the bottom plate 5 which is retained in the base I by means of the springs 6. On this bottom plate 5 is secured by solder or the like the three sided reflector 'I having its interior walls painted white to reect light from the lamp through the openings 9 and IU in the top plate of the member I and the bottom of the member 2, as hereinafter described.

The base I supports the sample containing portion 2. This porton 2 comprises the two compartments I8 and I9 having their outer walls 39 and 40 terminating in flanges adapted to rest on the base I and a center partition 20.

Over the openings 9 and I0 in the upper side of the base I is placed the ground glass light diffusing screen 4I, and over said screen 4I is a washer element 42 formed of rubber or the like and adapted to be held in -place by the lower end of the partition 20 which engages the upper surface of said washer element. The sample containers 2| and 22 are adapted to rest on said washer element 42.

The lamp 8 is secured in the socket 33 which has an extension 34 extending through the slot I I in the Wall of the base or casing I and which is adapted to be moved in said slot to position said lamp in desired relation with said openings 9 and I9 and then by tightening the knurled nut I 2 the lamp 8 is locked in adjusted position. This locking is effected by the tightening of the nut I 2 which yforces the members 34 and I4 to tightly engage the inner and outer surfaces of the casing surrounding the slot II. The current for the lamp is obtained through the cord 32 from an ordinary current supply.

Between the base of the socket 33 and the member 34 is secured a longitudinal strip member I5 which has its end portions IS and II extending out of the casing I through slotsin the sides thereof. These protruding end portions I6 and I'I allow the operator to adjust the lamp to desired position while looking into the eyepiece of the instrument and when the lamp 8 has been adjusted to desired position it may be locked in said position if desired by tightening the nut I2 as heretofore described.

The sample containing portion 2 is divided into two compartments I8 and I9 by the .partition 25J. The compartments I8 and I9 are adapted to support glass containers 2| and 22, one or both of which contains the sample of the liquid to be tested or the sample to be compared.

These glass containers 2I and 22 preferably portions 24 and 25 adapted to retain color standards 26. These portions 24 and 25 have aligned openings 35 and 36 to allow light to pass through v said portions 24 and 25 and into the prism 23. At its lower end the member 3 has a flange 31 adapted to t in telescoping relation with the upper end of the member 2. Adjacent the center of its lower end this member 3 has the two spaced projecting members 38 through one corner of which extends the screw or rivet 21. This rivet or screw 21 also extends through the slot 28 in the center partition 25 pivotally connecting the parts so that when it is desired to insert or remove the test containers 2| and 22 from the casing, the portion 3 may be lifted and pivoted out of the way as shown in Figs. 4 and 5. The screw or rivet 21 v retains the parts in aligned relation as shown in Figs. 1 and 2 and retains the parts in pivoted relation as shown in Figs. 4 and 5.

By removing the screw or rivet 21 the head of the instrument comprising the portion 3 and the eyepiece 4 may be removed for separate use either alone or with other accessory apparatus.

The eyepiece casing 4 contains the telescoping member 3| carrying the objective lens 29, daylight lter 30 and sight opening 43. This tube 3| is movable in the eyepiece casing 4 to focus the lens 29. The path of the light rays is shown in dotted lines in Fig. 1 of the drawing.

The operation of the colorimeter, which is of the Lovibond type is as follows:

A predetermined depth of the liquid or other substance to be tested is placed in one of the glass containers 2| or 22 and the other of said containers is left empty or used to contain a comparison substance and both of said containers are then placed in their respective compartments in the member 2.

The operator than looks through the eyepiece and puts in the color scale container a succession of colored standards, all of which are given numeral Values according to their color such as is represented by the well known Lovibond color scale, until the color of the combination of colored standards is the same as that of the liquid under test and then the combination of colored standards necessary to reproduce the color of the liquid sample indicates the color of the sample.

In some instances it has been found that while the sample and combination of colored standards may have the same hue and saturation, that they may not have the same light transmission or brightness and in such cases the nut |2 is loosened and then by moving the projections I6 and |1 back and forth with his hands while looking through the eyepiece the operator may adjust the lamp 8 until the same light transmission or brightness is obtained through both of the tubes, thus allowing a much sharper degree of comparison of the sample and standard than would otherwise be possible. The nut |2 may then be tightened to lock the lamp in adjusted position.

Alternatively the nut l2 may be left loose and the lamp 8 moved to introduce small brightness differences between the beams of light passing through the tubes I8 and i9. Asymmetry in the appearance of these color fields when they are alternately made light and dark is a sensitive test for an identity of color in the two fields.

It will be noted from the above description taken in conjunction with the accompanying drawing that we have provided a colorimeter wherein the upper portion may be easily and quickly pivoted out of the way to allow the sample to be easily and quickly inserted or removed, and that the upper portion or head of the instrument may be quickly and easily removed to allow for the measurement of samples not readily accommodated by the body of the instrument. Also, that the illuminating means may be adjusted to provide the same eiective light transmission or brightness in cases where the sample and color standards have the same hue and saturation but not the same inherent light transmission or brightness, and that the illuminating means may then be locked in adjusted position, if desired.

From the above it will be seen that we have provided simple, efficient and economical means for obtaining all of the objects and advantages of the invention.

Having described our invention, we claim:

l. A device of the character described comprising a source of illumination, a hollow specimen supporting portion and a head portion in optical alignment with said source of illumination, an eyepiece and an optical viewing element in said head portion, and the lower end of said head portion and upper end of said hollow specimen supporting portion being in telescoping relation and a pivotal connection adjacent the upper end of said hollow specimen supporting portion and the lower end of said head portion, to allow the said head portion to be raised and then pivoted out of alignment with said hollow specimen supporting portion for the removal or insertion of specimens in said hollow specimen supporting portion.

2. A device of the character described comprising a source of illumination, a hollow specimen supporting portion and a head portion in alignment with each other, said head portion comprising an eyepiece, a prism and a standard supporting portion, and the lower end of said head portion and upper end of said hollow specimen supporting portion being in telescoping relation, and a pivotal connection joining the upper end of said specimen supporting portion with the lower end of said head portion, to allow the said head portion to be raised and then pivoted out of alignment with said specimen supporting portion for the insertion or removal of specimens in said hollow specimen supporting portion.

3. A device of the character described comprising a source of illumination, a hollow specimen supporting member in alignment therewith, a head portion comprising an eyepiece, an optical element and a standard support in alignment with said source of illumination and hollow specimen supporting member, and the lower end of said head portion and the upper end of said hollow specimen supporting 'portion being in telescoping relation, the upper end of said hollow specimen supporting member and the lower end of said head portion being joined together by a pivotal connection comprising a vertical slot in a wall of one of said members and a projection on the other of said members having a pivot in said slot, to allow said head portion to be raised and then pivoted out of alignment with said hollow specimen supporting member.

ROGER S. ESTEY. KENNARD W. HARPER. 

